Trenton T4G, Техническое описание

Страница: 140 / 144

BIOS Messages T4G Technical Reference
TRENTON Technology Inc. A-8
P
OST
C
ODE
C
HECKPOINTS
The POST code checkpoints are the largest set of checkpoints during the BIOS pre-boot
process. The following table describes the type of checkpoints that may occur during the
POST portion of the BIOS:
Check-
point
Description
03
04
05
06
08
0A
0B
0C
0E
13
24
30
2A
2C
2E
31
33
37
Disable NMI, parity, video for EGA and DMA controllers. Initialize BIOS, POST,
Runtime data area. Also initialize BIOS modules on POST entry and GPNV area.
Initialize CMOS as mentioned in the Kernel Variable “wCMOSFlags.”
Check CMOS diagnostic byte to determine if battery power is OK and CMOS
checksum is OK. Verify CMOS checksum manually by reading storage area. If the
CMOS checksum is bad, update CMOS with power-on default values and clear
passwords. Initialize status register A. Initialize data variables that are based on
CMOS setup questions. Initialize both the 8259 compatible PICs in the system.
Initialize the interrupt controlling hardware (generally OPIC) and interrupt vector table.
Do read/write test to CH-2 count register. Initialize CH-0 as system timer. Install the
POSTINT1Ch handler. Enable IRQ-0 in PIC for system timer interrupt. Traps INT1Ch
vector to “POSTINT1ChHandlerBlock.”
Initialize the CPU. The BAT test is being done on KBC. Program the keyboard
controller command byte is being done after auto detection of keyboard/mouse using
AMI KB-5.
Initialize the 8042 compatible keyboard controller.
Detect the presence of PS/2 mouse.
Detect the presence of keyboard in KBC port.
Testing and initialization of different input devices. Also, update the Kernel variables.
Traps the INT09h vector, so that the POST INT09h handler gets control for IRQ1.
Uncompress all available language, BIOS logo and silent logo modules.
Early POST initialization of chipset registers.
Uncompress and initialize any platform specific BIOS modules.
Initialize System Management Interrupt.
Initialize different devices through DIM. See DIM Code Checkpoints section of this
appendix for more information.
Initialize different devices. Detects and initializes the video adapter installed in the
system.
Initialize all the output devices.
Allocate memory for ADM module and uncompress it. Give control to ADM module for
initialization. Initialize language and font modules for ADM. Activate ADM module.
Initialize the silent boot module. Set the window for displaying text information.
Display sign-on message, CPU information, setup key message and any OEM specific
information.